1. Field of the Invention
The invention relates to a backrest as a component of a motor vehicle seat which is comprised of a sheet metal shell and an upholstery member with an upholstery cover arranged thereon.
2. Description of the Related Art
In backrests of motor vehicle seats of known design, sheet metal shells which are reinforced by a tube frame are used in conjunction with upholstery members comprising an attached foam material in which so-called fabric catch wires are inserted. In the upholstery cover fabric loops are sewn in which must be threaded into the upholstery wires which are provided with eyes at their ends. When connecting the upholstery member, these eyes are suspended from the fabric catch wires which are present within the foam material. This provides a connection between the upholstery member and the upholstery cover. Subsequently, the outer edges of the upholstery cover are connected by means of piping with the sheet metal shell. Accordingly, in the seat area there is thus no connection between the upholstery cover and the sheet metal shell.
It is an object of the present invention to provide a backrest which, for the same construction space, provides a stiffer upholstery member and is furthermore advantageous with regard to manufacturing technological aspects.
In accordance with the present invention, this is achieved in that the upholstery member is fixed by securing elements on the sheet metal shell wherein each securing element is secured by a fastening leg in a cutout of the sheet metal shell and engages with a hook portion in the upholstery member, and the upholstery cover is coupled by a connector with the securing element.
The gist of the invention resides in the feature that the upholstery member is fixed by securing elements on the sheet metal shell wherein each securing element is attached with a fastening leg in a cutout of the sheet metal shell and penetrates with a hook portion into the upholstery member. The upholstery member is coupled by a connector to the securing element.
This results in a direct coupling of the upholstery cover and the sheet metal shell. The invention makes it possible to connect the upholstery member much faster to the sheet metal shell of the backrest and also allows the use of thicker foam materials as an upholstery member. This can provide a stiffer upholstery member within the same construction space.
The required cutouts are provided in the sheet metal shell of the backrest in defined positions. This can be done during the course of shaping of the shell or also in a further manufacturing step. The securing elements are inserted into these preferably quadrangular cutouts. The securing elements are expediently made of plastic material. Onto these the tailored foam part can be placed as an upholstery member. The upholstery member is now secured in its position for transport. The attachment or position orientation is ensured by the hook portions. Logistically, this is advantageous because the intermediate component can be delivered to the upholstery company in this state. At the upholstery company, the backrest is then covered by the upholstery cover wherein a coupling between the upholstery cover and the securing element is provided by a connector.
In this way, a direct connection between the upholstery cover and the sheet metal shell is ensured. With this measure, thicker upholstery materials or tighter upholstery members can be provided for the same amount of construction or mounting space. Moreover, the backrest is improved with regard to quality as well as with regard to its service life.
According to a preferred embodiment of the present invention, each cutout provided for the securing elements is arranged in a recess of the sheet metal shell that is set back in the direction toward the upholstery member. The fastening leg then does not project past the backside of the sheet metal shell. Also, it is possible to introduce the fingers into the recess to manually grip the fastening leg in order to detach the fastening leg and to demount a securing element.
The fastening leg according to a preferred embodiment of the invention has two spring-elastic spreading legs and an abutment positioned opposite the free ends of the spreading legs at a spacing matching the thickness of the sheet metal shell. A securing element can then snap with its clip-shaped fastening leg into the cutout without greater expenditure by simply being inserted and is then secured in its position. The spreading legs press against the sheet metal shell. On the inwardly positioned side of the sheet metal shell, the securing element is supported by its abutment.
Advantageously, at the free ends of the spreading legs recesses are provided which face away from one another. With these recesses the spreading legs are positioned at the surrounding sheet metal wall of the cutout.
According to another preferred embodiment of the invention, the hook portion has at least one barb positioned at an angle relative toward the sheet metal shell. The one or more barbs can be designed differently. They ensure a reliable securing action of the upholstery member during transport. Moreover, slipping of the upholstery member on the sheet metal shell underneath the upholstery cover is prevented in the finished backrest.
For producing a coupling between the connector and the securing element, according to a preferred embodiment of the invention the securing element has at a side opposite the fastening leg a receptacle engaged by the connector with its securing profile.
Even though constructively different designs of the receptacle are possible, an advantageous embodiment of the invention has a pocket-like design and is provided with two snap legs with securing pawls at their ends. Each snap leg is provided at its outer side with a recess extending transversely to the longitudinal extension of the snap legs and having a stay arrange approximately in the central area. With this, spring-elastic securing properties of the snap legs are enhanced in a positive way.
According to another preferred embodiment, the connector is comprised of a non-woven thread with an injection-molded pointed securing profile. The fabric loops which have been provided on upholstery covers of the prior art are replaced according to the invention by the connector of non-woven material with pointed securing profile. With the securing profile the connector is pressed into the receptacle of the securing element. In this connection, the snap legs engage with their securing pawls the securing profile. This results in a direct connection of the upholstery cover on the sheet metal shell via the connector and the securing element.
A further advantageous embodiment of the present invention is characterized in that the securing element has a central portion with a cross-shaped cross-section. The cross-shaped cross-section enhances the strength and increases the breakage resistance of the securing element.